December 22, 2005

Fish oil curbs heart trouble linked to pollution

By Megan Rauscher

NEW YORK (Reuters Health) - Daily supplementation with
omega-3 fatty acid (fish oil) prevents a potentially-deadly
decline in heart rate variability (HRV) associated with
exposure to indoor air pollution, researchers from the US and
Canada report.

HRV measures the variability in the intervals between
heartbeats, with lower variability being associated with higher
risks of heart disease and death.

"Imagine," explained Dr. Fernando Holguin, "that a normal
heart does not always have the same time intervals between
beats, but every so often (in cycles) the interval between
cardiac beats changes; i.e. a little shorter, or longer. How
frequent these variations occur are a measure of the effect of
the nervous regulation of the heart. It is a fine-tuning that
we are not aware of. A sick heart losses this fine tuning."

In the elderly, exposure to fine particulate matter, a
common air pollutant, has been associated with reductions in
HRV. But in their study of 50 relatively healthy elderly
nursing home residents, Holguin and colleagues found that a
daily two-gram fish oil supplement prevented a decline in HRV.

Supplementation with soy "control" oil, on the other hand,
did not offer significant protection against the harmful
effects of indoor air pollution on HRV.

Holguin, from the Centers for Disease Control and
Prevention, and colleagues report their finding in the American
Journal of Respiratory and Critical Care Medicine.

"A lower HRV may increase the risk of a susceptible person
to have a serious cardiac arrhythmia," Holguin told Reuters
Health. "In the future, when we identify who is most
susceptible to the effects of particulate matter, we could
recommend supplementation with omega-3 fatty acids to reduce
their cardiovascular risk," he added.

SOURCE: American Journal of Respiratory and Critical Care
Medicine, December 2005.